try:
    height = float(input("请输入身高（单位：米）："))
    weight = float(input("请输入体重（单位：千克）："))
    bmi = weight / (height * height)
    if bmi < 18.5:
        print("您的BMI指数为：", bmi, "过轻")
    elif 18.5 <= bmi < 25:
        print("您的BMI指数为：", bmi, "正常")
    elif 25 <= bmi < 28:
        print("您的BMI指数为：", bmi, "过重")
    elif 28 <= bmi < 32:
        print("您的BMI指数为：", bmi, "肥胖")
    else:
        print("您的BMI指数为：", bmi, "严重肥胖")
except ValueError:
    print("输入的不是数字，请重新输入！")
